Challenges and Enhancing Strategies of Equine Semen Preservation: Nutritional and Genetic Perspectives

Abstract

Equine semen preservation is fundamental to modern equine reproduction, supporting breeding programs, genetic conservation, and industry sustainability. However, significant challenges persist, including temperature sensitivity, oxidative stress, bacterial contamination, individual variability, and lack of standardized preservation protocols. These factors contribute to reduced sperm viability and fertility following cryopreservation. This review examines critical obstacles in equine semen preservation, focusing on cryopreservation sensitivity, molecular damage mechanisms, economic constraints, and seasonal quality variations. We analyze the molecular and structural alterations (e.g., oxidative stress, membrane damage, and DNA fragmentation) and their impact on cryopreservation success. The review evaluates evidence-based enhancement strategies, including nutritional supplementation and genetic approaches, for improving semen quality. Nutritional interventions that utilize antioxidants, polyunsaturated fatty acids (PUFAs), and nutraceuticals have demonstrated promising results in enhancing sperm motility, preserving membrane integrity, and improving overall semen quality. Additionally, we discuss key candidate genes associated with equine semen-quality traits, including sperm motility, viability, and cryotolerance. The integration of nutritional supplementation and genetic selection strategies presents viable pathways for optimizing equine semen preservation techniques. These combined approaches offer potential solutions for overcoming current limitations, ultimately supporting sustainable breeding programs and advancing genetic conservation efforts in the equine industry.